Verbseoul.
하다 verb (adj)
착하다chakhadato be good-hearted, to be kind, to be nice

To say to be good-hearted, to be kind, to be nice politely in the present tense, use 착해요 (chah-kae-yoh). Below is the full conjugation of 착하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
착해
chah-kae
착해요
chah-kae-yoh
착합니다
chah-kahm-nee-dah
Past
착했어
chah-kae-ssuh
착했어요
chah-kae-ssuh-yoh
착했습니다
chah-kae-sseum-nee-dah
Future
착할 거야
chah-kahl- -guh-yah
착할 거예요
chah-kahl- -guh-yae-yoh
착할 겁니다
chah-kahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
착하세요
chah-kah-sae-yoh
Suggestion / Let's Polite (요)
착해요
chah-kae-yoh
Question Polite (요)
착해요?
chah-kae-yoh-?
Connective “and” — (고)
착하고
chah-kah-goh
Conditional “if” — (면)
착하면
chah-kah-myuhn
Noun form — (기)
착함
chah-kahm